We used to depend on CONFIG_SWIOTLB, but that is disabled by default.
So when compiling we get this compile error:

arch/x86/xen/pci-swiotlb-xen.c: In function 'pci_xen_swiotlb_detect':
arch/x86/xen/pci-swiotlb-xen.c:48: error: lvalue required as left operand of assignment

Fix it by actually activating the SWIOTLB library.
Reported-by: NStefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

It used to done in the Xen startup code but that is not really
appropiate.

[v2: Update Kconfig with PCI requirement]
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

This is a port of the 2.6.18 Xen PCI front driver with fixes
to make it build under 2.6.34 and later (for the full list of
changes: git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen.git
historic/xen-pcifront-0.1). It also includes the fixes
to make it work properly.

[v2: Updated Kconfig, removed crud, added Reviewed-by]
[v3: Added 'static', fixed grant table leak, redid Kconfig]
[v4: Added one more 'static' and removed comments]
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: NStefano Stabellini <stefano.stabellini@eu.citrix.com>
Reviewed-by: NJan Beulich <JBeulich@novell.com>

XenbusStateReconfiguring/XenbusStateReconfigured were introduced by
c/s 437, but aren't handled in many switch statements.

.. also pulled from the linux-2.6-sparse-tree tree.
Signed-off-by: NJan Beulich <jbeulich@novell.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>

The Xen PCI front driver adds two new states that are utilizez
for PCI hotplug support. This is a patch pulled from the
linux-2.6-xen-sparse tree.
Signed-off-by: NNoboru Iwamatsu <n_iwamatsu@jp.fujitsu.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: NYosuke Iwamatsu <y-iwamatsu@ab.jp.nec.com>

The frontend stub lives in arch/x86/pci/xen.c, alongside other
sub-arch PCI init code (e.g. olpc.c).

It provides a mechanism for Xen PCI frontend to setup/destroy
legacy interrupts, MSI/MSI-X, and PCI configuration operations.

[ Impact: add core of Xen PCI support ]
[ v2: Removed the IOMMU code and only focusing on PCI.]
[ v3: removed usage of pci_scan_all_fns as that does not exist]
[ v4: introduced pci_xen value to fix compile warnings]
[ v5: squished fixes+features in one patch, changed Reviewed-by to Ccs]
[ v7: added Acked-by]
Signed-off-by: NAlex Nixon <alex.nixon@citrix.com>
Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: NIan Campbell <ian.campbell@citrix.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: NStefano Stabellini <stefano.stabellini@eu.citrix.com>
Acked-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Matthew Wilcox <willy@linux.intel.com>
Cc: Qing He <qing.he@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: x86@kernel.org

Introduce an x86 specific indirect mechanism to setup MSIs.
The MSI setup functions become function pointers in an x86_msi_ops
struct, that defaults to the implementation in io_apic.c and msi.c.

[v2: Use HAVE_DEFAULT_* knobs]
Signed-off-by: NStefano Stabellini <stefano.stabellini@eu.citrix.com>
Reviewed-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: x86@kernel.org
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>

Introduce an override for the arch_[teardown|setup]_msi_irqs
that can be utilized to fallback to the default arch_* code.

If a platform wants to utilize the code paths defined
in driver/pci/msi.c it has to define HAVE_DEFAULT_MSI_TEARDOWN_IRQS
or HAVE_DEFAULT_MSI_SETUP_IRQS. Otherwise the old mechanism
of over-ridding the arch_* works fine.
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: x86@kernel.org

In preperation of modularizing Xen-pcifront the pci_walk_bus
needs to be exported so that the xen-pcifront module can walk
call the pci subsystem to walk the PCI devices and claim them.
Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: Jesse Barnes <jbarnes@virtuousgeek.org> [http://marc.info/?l=linux-pci&m=126149958010298&w=2]

When mapping pci space via /sys or /proc, make sure we're really
doing a hardware mapping by setting _PAGE_IOMAP.

[ Impact: bugfix; make PCI mappings map the right pages ]
Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Reviewed-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: N"H. Peter Anvin" <hpa@zytor.com>
Reviewed-by: NMatthew Wilcox <willy@linux.intel.com>
Acked-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Cc: x86@kernel.org

Separate out x86 cache_line_size initialisation code into its own
function (so it can be shared by Xen later in this patch series)

[ Impact: cleanup ]
Signed-off-by: NAlex Nixon <alex.nixon@citrix.com>
Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: N"H. Peter Anvin" <hpa@zytor.com>
Reviewed-by: NMatthew Wilcox <willy@linux.intel.com>
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Cc: x86@kernel.org

In driver/xen/events.c, whether bind_pirq is shareable or not is
determined by desc->action is NULL or not. But in __setup_irq,
startup(irq) is invoked before desc->action is assigned with
new action. So desc->action in startup_irq is always NULL, and
bind_pirq is always not shareable. This results in pt_irq_create_bind
failure when passthrough a device which shares irq to other devices.

This patch doesn't use probing_irq to determine if pirq is shareable
or not, instead set shareable flag in irq_info according to trigger
mode in xen_allocate_pirq. Set level triggered interrupts shareable.
Thus use this flag to set bind_pirq flag accordingly.

[v2: arch/x86/xen/pci.c no more, so file skipped]
Signed-off-by: NWeidong Han <weidong.han@intel.com>
Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

The 'xen_poll_irq_timeout' provides a method to pass in
the poll timeout for IRQs if requested. We also export
those two poll functions as Xen PCI fronted uses them.
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>

In earlier Xen Linux kernels, the IRQ mapping was a straight 1:1 and the
find_unbound_irq started looking around 256 for open IRQs and up. IRQs
from 0 to 255 were reserved for PCI devices.  Previous to this patch,
the 'find_unbound_irq'  started looking at get_nr_hw_irqs() number.
For privileged  domain where the ACPI information is available that
returns the upper-bound of what the GSIs. For non-privileged PV domains,
where ACPI is no-existent the get_nr_hw_irqs() reports the IRQ_LEGACY (16).
With PCI passthrough enabled, and with PCI cards that have IRQs pinned
to a higher number than 16 we collide with previously allocated IRQs.
Specifically the PCI IRQs collide with the IPI's for Xen functions
(as they are allocated earlier).
For example:

00:00.11 USB Controller: ATI Technologies Inc SB700 USB OHCI1 Controller (prog-if 10 [OHCI])
	...
	Interrupt: pin A routed to IRQ 18

[root@localhost ~]# cat /proc/interrupts | head
           CPU0       CPU1       CPU2
 16:      38186          0          0   xen-dyn-virq      timer0
 17:        149          0          0   xen-dyn-ipi       spinlock0
 18:        962          0          0   xen-dyn-ipi       resched0

and when the USB controller is loaded, the kernel reports:
IRQ handler type mismatch for IRQ 18
current handler: resched0

One way to fix this is to reverse the logic when looking for un-used
IRQ numbers and start with the highest available number. With that,
we would get:

           CPU0       CPU1       CPU2
... snip ..
292:         35          0          0   xen-dyn-ipi       callfunc0
293:       3992          0          0   xen-dyn-ipi       resched0
294:        224          0          0   xen-dyn-ipi       spinlock0
295:      57183          0          0   xen-dyn-virq      timer0
NMI:          0          0          0   Non-maskable interrupts
.. snip ..

And interrupts for PCI cards are now accessible.

This patch also includes the fix, found by Ian Campbell, titled
"xen: fix off-by-one error in find_unbound_irq."

[v2: Added an explanation in the code]
[v3: Rebased on top of tip/irq/core]
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>

Sometimes cpu_evtchn_mask_p can get used early, before it has been
allocated.  Statically initialize it with an initdata version to catch
any early references.
Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

Impact: cleanup

Make pirq show useful information in /proc/interrupts

[v2: Removed the parts for arch/x86/xen/pci.c ]
Signed-off-by: NGerd Hoffmann <kraxel@xeni.home.kraxel.org>
Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

Dynamically allocate the irq_info and evtchn_to_irq arrays, so that
1) the irq_info array scales to the actual number of possible irqs,
and 2) we don't needlessly increase the static size of the kernel
when we aren't running under Xen.

Derived on patch from Mike Travis <travis@sgi.com>.

[Impact: reduce memory usage ]
[v2: Conflict in drivers/xen/events.c: Replaced alloc_bootmen with kcalloc ]
Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

Impact: preserve compat with native

Reserve the lower irq range for use for hardware interrupts so we
can identity-map them.

[v2: Rebased on top tip/irq/core]
Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

Impact: new interface to get max GSI

Add get_nr_irqs_gsi() to return nr_irqs_gsi.  Xen will use this to
determine how many irqs it needs to reserve for hardware irqs.
Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: N"H. Peter Anvin" <hpa@zytor.com>
Acked-by: NThomas Gleixner <tglx@linutronix.de>
Cc: x86@kernel.org
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>

A privileged PV Xen domain can get direct access to hardware.  In
order for this to be useful, it must be able to get hardware
interrupts.

Being a PV Xen domain, all interrupts are delivered as event channels.
PIRQ event channels are bound to a pirq number and an interrupt
vector.  When a IO APIC raises a hardware interrupt on that vector, it
is delivered as an event channel, which we can deliver to the
appropriate device driver(s).

This patch simply implements the infrastructure for dealing with pirq
event channels.

[ Impact: integrate hardware interrupts into Xen's event scheme ]
Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

Impact: allow Xen control of bio merging

When running in Xen domain with device access, we need to make sure
the block subsystem doesn't merge requests across pages which aren't
machine physically contiguous.  To do this, we define our own
BIOVEC_PHYS_MERGEABLE.  When CONFIG_XEN isn't enabled, or we're not
running in a Xen domain, this has identical behaviour to the normal
implementation.  When running under Xen, we also make sure the
underlying machine pages are the same or adjacent.
Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

If a guest domain wants to access PCI devices through the frontend
driver (coming later in the patch series), it will need access to the
I/O space.

[ Impact: Allow for domU IO access, preparing for pci passthrough ]
Signed-off-by: NAlex Nixon <alex.nixon@citrix.com>
Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

The core code now initializes the requested number of interrupts and
sets the flags in irq_desc.status which are requested by the
architecture via ARCH_IRQ_INIT_FLAGS.

Add ARCH_IRQ_INIT_FLAGS and remove the loop which sets those flags
after the irq descriptors are allocated.

[ This patch should have been in the original irq rework and got
  dropped accidentaly ]
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Linus Walleij <linus.walleij@stericsson.com>
Cc: Anand Gadiyar <gadiyar@ti.com>

Commit b683de2b in linux-next as of 20101014 (genirq: Query
arch for number of early descriptors) seems to have broken
bootup on several ARM boards - my beagleboard gives the
following dump with earlyprintk:

 NR_IRQS:402
 Unable to handle kernel NULL pointer dereference at virtual
 address 00000028 pgd = c0004000
 [00000028] *pgd=00000000
 Internal error: Oops: 5 [#1]
 last sysfs file:
 Modules linked in:
 CPU: 0    Not tainted
 (2.6.36-rc7-next-20101014-linux-next-20101012+ #40) PC is at
 init_IRQ+0x14/0x48 LR is at start_kernel+0x150/0x2c0
 [...]

We seem to be using desc->status without assigning desc to
anything. Fix this by adding back the code that was originally
there.
Signed-off-by: NAnand Gadiyar <gadiyar@ti.com>
Tested-by: NLinus Walleij <linus.walleij@stericsson.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: linux-arm-kernel@lists.infradead.org
LKML-Reference: <1287077397-21781-1-git-send-email-gadiyar@ti.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

This option can be set to verify the full conversion to the new chip
functions. Fix the fallout of the patch rework, so the core code
compiles and works with it.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

No callers from atomic context (except boot) anymore.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NIngo Molnar <mingo@elte.hu>

The allocator functions are now called outside of preempt disabled
regions. Switch to GFP_KERNEL.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NIngo Molnar <mingo@elte.hu>

No callers from atomic regions. 
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NIngo Molnar <mingo@elte.hu>

Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NIngo Molnar <mingo@elte.hu>
Cc: Rusty Russell <rusty@rustcorp.com.au>

The move_irq_desc() function was only used due to the problem that the
allocator did not free the old descriptors. So the descriptors had to
be moved in create_irq_nr(). That's history.

The code would have never been able to move active interrupt
descriptors on affinity settings. That can be done in a completely
different way w/o all this horror.

Remove all of it.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NIngo Molnar <mingo@elte.hu>

Use the cleanup functions of the dynamic allocator. No need to have
separate implementations.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NIngo Molnar <mingo@elte.hu>

This function should have not been there in the first place.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NIngo Molnar <mingo@elte.hu>

There seems to be more cleanups possible, but that's left to the xen
experts :)
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NIngo Molnar <mingo@elte.hu>
Cc: Jeremy Fitzhardinge <jeremy@xensource.com>

Instead of looping through all interrupts, use the bitmap lookup to
find the next.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NIngo Molnar <mingo@elte.hu>

Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NIngo Molnar <mingo@elte.hu>

No users outside of io_apic.c
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NIngo Molnar <mingo@elte.hu>

irq_2_iommu is now in the x86 code where it belongs. Remove all
leftovers.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NIngo Molnar <mingo@elte.hu>
Acked-by: NSuresh Siddha <suresh.b.siddha@intel.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>

irq_2_iommu is in struct irq_cfg, so we can do the irq_remapped check
based on irq_cfg instead of going through a lookup function. That's
especially interesting in the eoi_ioapic_irq() hotpath.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NIngo Molnar <mingo@elte.hu>
Acked-by: NSuresh Siddha <suresh.b.siddha@intel.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>

Having irq_2_iommu in struct irq_cfg allows further simplifications.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NIngo Molnar <mingo@elte.hu>
Acked-by: NSuresh Siddha <suresh.b.siddha@intel.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>